[Screening for asymptomatic atrial fibrillation in elder community populations in Dalian: a single center study]

Objective: We aimed to determine the epidemiological characteristics of asymptomatic AF in elder community population (≥65 years old) to analyze the detection rate of different screening methods. Methods: The study was a prospective cohort study. The elder (≥65 years old) residents who voluntarily participated in free physical examination in Dalian community were selected. The participants were randomly divided into screening group (including intensive screening group and single screening group) and control group. The control group received interrogation, medical history collection and routine 12-lead electrocardiogram (ECG) examination. Screening group received an additional single-lead ambulatory ECG equipment worn for 5-7 days. Intensive screening group received two equal-length wearings in 2020 and 2021 respectively, while one screening group only wore once in 2020. Results: Finally 3 340 residents ((70.7±5.0) years old) which consisted of 1 488 males (44.55%) were enrolled. There were 1 945 residents in screening group, including 859 in intensive screening group and 1 086 in one-time screening group. The control group included 1 395 people. Detection rate of asymptomatic AF was significantly higher in screening group than control group (79(4.06%) vs. 24(1.72%), P<0.001). Higher detection rate was found in screening group than control group in AF risk factors (1 or 2-3) subgroups and CHA2DS2-VASc score (2-3 or≥4) subgroups (P<0.05). Additionally, no difference was found between intensive screening group and single screening group (42(4.89%) vs. 37(3.41%), P=0.100). Intensive screening increased detection rate (7(6.93%) vs. 1(0.58%), P=0.009) only in residents those with low thrombosis risk (CHA2DS2-VaSc<2). Conclusions: Screening in elderly (≥65 years old) can significantly improve the detection rate of asymptomatic AF by wearing single lead dynamic ECG device. The rate increased significantly with the increase of risk factors associated with AF by single screening. In addition, repeat screening of the same method may only improve detection rates in the group with low risk thrombotic scores and non-combination of AF risk factors.Screening methods that are appropriate for different populations may require further exploration.

Associations of brachial-ankle pulse wave velocity with left atrial stiffness and left atrial phasic function in inpatients with hypertension

Hypertension induces left atrial (LA) and left ventricular (LV) dysfunction, and an increase in arterial stiffness. This study aimed to investigate the associations of brachial-ankle pulse wave velocity (baPWV) with LA stiffness and LA phasic function in hypertension. A total of 305 hypertensive inpatients enrolled and were divided into two groups based on baPWV [Group I, baPWV ≤ 1515 (cm/s), n = 153; Group II, baPWV > 1515 (cm/s), n = 152]. Two-dimensional speckle tracking echocardiography (2D-STE) based LA phasic strains (LAS-S, LAS-E, LAS-A) and LV global longitudinal strain (LVGLS) were evaluated. LA stiffness index (LASI) was defined as the ratio of E/e' to LAS-S. Multivariate linear regression modeling was used to analyze the associations of baPWV with LASI and LA phasic function in all patients as well as age-specific and sex-specific subgroups. LASI was significantly higher in Group II [0.35(0.26, 0.52)] compared with Group I [0.26(0.20, 0.36)] (P < 0.001). After adjusting cardiovascular risk factors, medication, and LV structural and functional parameters (LVEF, LVMI, E/A ratio, and LVGLS), baPWV remained significantly correlated with LASI (P < 0.05). We also evaluated the predictive value of baPWV for LASI, the area under the curve (AUC) was 0.663 (95% CI: 0.607-0.716, P < 0.001). In conclusion, BaPWV was independently associated with LA stiffness in hypertensive inpatients. BaPWV also exhibited a certain predictive value for LA stiffness in these inpatients. Measuring arterial stiffness can provide clinicians clues for early cardiac target organ damage (TOD) in addition to vascular TOD.

Association Between Segmental Noninvasive Myocardial Work and Microvascular Perfusion in ST-Segment Elevation Myocardial Infarction: Implications for Left Ventricular Functional Recovery and Clinical Outcomes

BACKGROUND

Predicting left ventricular recovery (LVR) after acute ST-segment elevation myocardial infarction (STEMI) is of prognostic importance. This study aims to explore the prognostic implications of segmental noninvasive myocardial work (MW) and microvascular perfusion (MVP) after STEMI.

METHODS

In this retrospective study, 112 patients with STEMI who underwent primary percutaneous coronary intervention and transthoracic echocardiography after percutaneous coronary intervention were enrolled. Microvascular perfusion was analyzed by myocardial contrast echocardiography, and segmental MW was analyzed by noninvasive pressure-strain loops. A total of 671 segments with abnormal function at baseline were analyzed. The degrees of MVP were observed following intermittent high-mechanical index impulses: replenishment within 4 seconds (normal MVP), replenishment >4 seconds and within 10 seconds (delayed MVP), and persistent defect (microvascular obstruction). The correlation between MW and MVP was analyzed. The correlation of the MW and MVP with LVR (normalization of wall thickening, >25%) was assessed. The prognostic value of segmental MW and MVP for cardiac events (cardiac death, admission for congestive heart failure, or recurrent myocardial infarction) was evaluated.

RESULTS

Normal MVP was seen in 70 segments, delayed MVP in 236, and microvascular obstruction in 365. The segmental MW indices were independently correlated with MVP; 244 (36.4%) segments had segmental LVR at 3-month follow-up. Segmental MW efficiency and MVP were independently associated with segmental LVR (P < .05). The χ2 of combination of segmental MW efficiency and MVP was higher than either index alone for identifying segmental LVR (P < .001). At a median follow-up of 42.0 months, cardiac events occurred in 13 patients; all regional MW parameters, high sensitivity troponin I, regional longitudinal strain, and so on were associated with cardiac events.

CONCLUSIONS

Segmental MW indices are associated with MVP within the infarct zone following reperfused STEMI. Both are independently associated with segmental LVR, and regional MW is associated with cardiac events, providing prognostic value in STEMI patients.

Influence of Microalloying on the Microstructures and Properties of Spalling-Resistant Wheel Steel

Microalloyed steels have emerged to replace conventional plain-carbon steels to achieve longer wheel life on Chinese railroads. In this work, with the aim of preventing spalling, a mechanism that consists of ratcheting and shakedown theory correlated with steel properties is systematically investigated. Mechanical and ratcheting tests were carried out for microalloyed wheel steel to which vanadium was added in the range of 0-0.15 wt.% and the results were compared with that obtained for conventional plain-carbon wheel steel. The microstructure and precipitation were characterized via microscopy. As a result, the grain size was not obviously refined, and the pearlite lamellar spacing decreased from 148 nm to 131 nm in microalloyed wheel steel. Moreover, an increase in the number of vanadium carbide precipitates was observed, which were mainly dispersed and uneven, and precipitated in the pro-eutectoid ferrite region, in contrast to the observation of lower precipitation in the pearlite. It has been found that vanadium addition can lead to an increase in yield strength by precipitation strengthening, with no reduction or increase in tensile strength, elongation or hardness. The ratcheting strain rate for microalloyed wheel steel was determined to be lower than that for plain-carbon wheel steel via asymmetrical cyclic stressing tests. An increase in the pro-eutectoid ferrite content leads to beneficial wear, which can diminish spalling and surface-initiated RCF.

Development and Validation of a Nomogram for Estimation of Left Atrial Thrombus or Spontaneous Echo Contrast Risk in Non-Valvular Atrial Fibrillation Patients with Low to Borderline CHA2DS2-VASc Score

Purpose

Left atrial thrombus (LAT)/left atrial spontaneous echo contrast (LASEC) still exists in CHA₂DS₂-VASc score-defined low/borderline risk population. The purpose of this study is to explore the risk factors that associate with LAT/SEC and to create a nomogram to predict LAT/SEC risk in NVAF patients with low/borderline CHA₂DS₂-VASc scores.

Patients and Methods

A total of 834 NVAF patients with complete data on transesophageal echocardiography (TEE) were included in this study. Univariate and multivariate logistic regression analyses were performed to identify the risk factors that associate with LAT/SEC, and a nomogram was established based on the results. Receiver operating characteristic curve (ROC), calibration curve and decision curve analysis were performed to verify the predictive power of nomogram.

Results

The rates for LAT/SEC for the training and validation cohorts were 84 (14.7%) and 30 (11.4%), respectively. Independent factors including age, left ventricular ejection fraction (LVEF), left atrial diameter (LAD), smoke, non-paroxysmal AF (NPAF), and E/e’ were considered to construct the nomogram for LAT/SEC. The AUC for nomogram was 0.839 and 0.811 in the training and validation cohorts, respectively. The calibration and decision curve analysis showed that the nomogram had a good prediction capacity and would be clinically useful.

Conclusion

Age, LVEF, LAD, smoke, NPAF, and E/e’ are independently associated with LAT/SEC in NVAF patients with low/borderline CHA₂DS₂-VASc scores. The nomogram that incorporates these six variables effectively predict LAT/SEC risk in NVAF patients with low/borderline CHA₂DS₂-VASc scores.

Anthracycline-Induced Atrial Structural and Electrical Remodeling Characterizes Early Cardiotoxicity and Contributes to Atrial Conductive Instability and Dysfunction

Aims: Cancer patients treated with anthracyclines are susceptible to atrial fibrillation (AF), while the mechanisms remain unclear. Due to sudden and unpredictable features, prediction of anthracycline-induced AF at early phase is difficult. Clinically, we tested whether anthracycline-induced early atrial remodeling in patients could be detected by echocardiography. Experimentally, we investigated the mechanisms of doxorubicin-induced atrial remodeling and AF in mice, and the protective effects of dexrazoxane and antioxidants. Methods and Results: Postsurgery breast cancer patients with an anthracycline-containing or anthracycline exclusion regimen were recruited for echocardiography before chemotherapy, and 3 and 6 months after chemotherapy. Mice were injected with doxorubicin or vehicle (5 mg/kg/week, 4 weeks), and left atrial diameter, electrical transmission, and AF inducibility were measured. Meanwhile, the level of reactive oxygen species (ROS), activity of antioxidant enzymes, cardiomyocyte size, vacuolization, inflammation, and fibrosis were also measured in mouse atria. The therapeutic effects of dexrazoxane and antioxidants on doxorubicin-induced changes in the aforementioned parameters were also determined. While ventricular parameters and functions were unchanged in cancer patients receiving anthracyclines before and after chemotherapy, left atrial reservoir and conduit function were decreased at 3 months postchemotherapy versus prechemotherapy. Doxorubicin-induced susceptibility to AF occurred in mice before onset of ventricular dysfunction. Doxorubicin-induced AF was via inducing structural remodeling (cardiomyocyte death, hypotrophy, and vacuolization) and electrical remodeling (reduction and redistribution of connexin 43) in atria, which was effectively prevented by dexrazoxane or antioxidants through inhibiting ROS generation or enhancing ROS elimination. Innovation and Conclusion: AF inducibility was induced after doxorubicin injection, which can be inhibited by repressing the ROS level. Antioxid. Redox Signal. 37, 19-39. The Clinical Trial Registration number is PJ-KS-KY-2019-73.

Case Report: Multimodal Imaging Guides the Management of an Eosinophilic Leukemia Patient With Eosinophilic Myocarditis and Intracardiac Thrombus

Background

Eosinophilic leukemia (EL) is a rare, serious and potentially life-threatening condition characterized by the overproduction of eosinophils leading to tissue eosinophilic infiltration and damage. Although multiple organ systems may be involved, progressive eosinophilic myocarditis (EM) is the most common cause of morbidity and mortality. Early diagnosis and follow-up surveillance combined with multimodal imaging are crucial for appropriate treatment of EM.

Case Summary

It’s a rare case of EL with EM and intracardiac thrombus in a 59-year-old patient who presented with asthenia for 3 weeks. Full blood count analysis indicated significant eosinophilia. Bone marrow aspirate revealed dysplastic eosinophilia and a FIP1L1-PDGFRA fusion gene (4q12) was detected, confirming EL. Echocardiography revealed EM with intracardiac thrombus. This was later confirmed by cardiac magnetic resonance imaging. The patient was commenced on imatinib and prednisolone and good clinical response was obtained. Through 18F-FAPI PET/CT imaging, we obtained in vivo visualization of fibroblast activation changes in the early stage of cardiac structure remodeling. With anti-fibrotic therapy after heart failure, the patient achieved a good clinical response.

Conclusion

This case demonstrates in vivo visualization of fibroblast activation after EM. Multimodality imaging can provide early diagnosis and may guide tailored antifibrotic therapy in early stage of EM.

Evaluation of left atrial function and mechanical dispersion in breast cancer patients after chemotherapy

BACKGROUND

Left atrial (LA) function and mechanical dispersion changes in breast cancer patients treated with chemotherapy remain unclear.

HYPOTHESIS

LA function and LA mechanical dispersion in breast cancer patients would be impaired after chemotherapy.

METHODS

This single-center retrospective study included 91 consecutive breast cancer patients treated with chemotherapy and 30 controls. Patients were examined by echocardiography three times at intervals. Conventional parameters, left ventricular strain, LA strain, and LA mechanical dispersion were evaluated and compared.

RESULTS

LA strain during reservoir phase (LASr), conduit phase (LAScd), and contraction phase (LASct) all decreased markedly after chemotherapy and were lower than those of the controls (all p < .01). The standard deviation of time to peak positive strain during LA reservoir phase corrected by R-R interval (LA SD-TPSr) was significantly increased after chemotherapy and was higher than that of the controls (p < .001). The change of LA function was expressed as Δ. Multivariate linear regression analyses showed that LAVIp (0.399, 95% confidence interval [CI]: 0.610, 1.756, p = .000) was independently associated with ΔLASr, LAPEF (-0.325, 95% CI: -45.123, -10.676, p = .002) and age (0.227, 95% CI: 0.021, 0.350, p = .027) were independently associated with ΔLAScd, and LAVImax (0.341, 95% CI: 0.192, 0.723, p = .001) was independently associated with ΔLASct. LAVImax (0.505, 95% CI: 0.000, 0.001, p = .039) and mitral E (-0.256, 95% CI: 0.000, 0.000, p = .024）were independently associated with ΔLA SD-TPSr.

CONCLUSIONS

Mechanical function of LA declined after chemotherapy in breast cancer patients. With the decrease of LA mechanical function, LA mechanical dispersion assessed by two-dimensional speckle-tracking echocardiography increased significantly, and its clinical value needs to be further studied.

Nomogram to Predict Left Atrial Thrombus or Spontaneous Echo Contrast in Patients With Non-valvular Atrial Fibrillation

Background: The predictive power of the CHADS₂ and CHA₂DS₂-VASc scores for the presence of Left atrial thrombus (LAT)/ spontaneous echo contrast (SEC) in non-valvular atrial fibrillation (NVAF) is modest. The aim of this analysis is to define clinical and ultrasonic variables associated with LAT/SEC and to propose nomograms for individual risk prediction.

Methods: Data on 1,813 consecutive NVAF patients who underwent transesophageal echocardiography (TEE) from January 2016 to January 2021 were collected. The univariate and multivariate logistic regression analyses were used to construct a nomogram. We examined the predictive ability of the risk scores by calculating the area under the curve (AUC). Moreover, the performance of the nomogram was assessed with respect to calibration, discrimination, and clinical usefulness.

Results: LAT/SEC was found in 260 (21.0%) and 124 (21.6%) patients in the training and validation cohorts, respectively. On multivariate analysis, independent factors for LAT/SEC were Age, left atrial diameter (LAD), left ventricular ejection fraction (LVEF), hypertension (HTN), previous stroke or transient ischemic attack, Non-paroxysmal AF and a nomogram was built based on these variables. The calibration curve for the probability of LAT/SEC showed good prediction agreement with actual observation. The nomogram achieved good concordance indexes of 0.836 and 0.794 in predicting LAT/SEC in the training and validation cohorts, respectively. Decision curve analysis demonstrated that the nomogram would be clinically useful.

Conclusions: In this study, a nomogram was constructed that incorporated six characteristics of NVAF patients. The nomogram may be of great value for the prediction of LAT/SEC in NVAF patients.

SCN11A gene deletion causes sensorineural hearing loss by impairing the ribbon synapses and auditory nerves

Background

The SCN11A gene, encoded Nav1.9 TTX resistant sodium channels, is a main effector in peripheral inflammation related pain in nociceptive neurons. The role of SCN11A gene in the auditory system has not been well characterized. We therefore examined the expression of SCN11A in the murine cochlea, the morphological and physiological features of Nav1.9 knockout (KO) ICR mice.

Results

Nav1.9 expression was found in the primary afferent endings beneath the inner hair cells (IHCs). The relative quantitative expression of Nav1.9 mRNA in modiolus of wild-type (WT) mice remains unchanged from P0 to P60. The number of presynaptic CtBP2 puncta in Nav1.9 KO mice was significantly lower than WT. In addition, the number of SGNs in Nav1.9 KO mice was also less than WT in the basal turn, but not in the apical and middle turns. There was no lesion in the somas and stereocilia of hair cells in Nav1.9 KO mice. Furthermore, Nav1.9 KO mice showed higher and progressive elevated ABR threshold at 16 kHz, and a significant increase in CAP thresholds.

Conclusions

These data suggest a role of Nav1.9 in regulating the function of ribbon synapses and the auditory nerves. The impairment induced by Nav1.9 gene deletion mimics the characters of cochlear synaptopathy.

Left atrial stiffness index as a marker of early target organ damage in hypertension

This study aimed to evaluate left atrial (LA) mechanics using two-dimensional speckle-tracking echocardiography (2DSTE) and investigate their correlations with measures of target organ damage (TOD) in hypertension. We enrolled 42 healthy controls (Group I) and 286 hypertension patients: Group II (n = 79) had an LA volume index (LAVI) <28 ml/m²; Group III (n = 92) had an LAVI ≥28 ml/m²; and Group IV (n = 115) had hypertension with left ventricular hypertrophy (LVH). We measured the following parameters: LA reservoir strain and strain rate (LA_S-S, LA_SR-S), LA conduit strain and strain rate (LA_S-E and LA_SR-E), and LA booster strain and strain rate (LA_S-A and LA_SR-A). The LA stiffness index (LASI) was defined as the ratio of early diastolic transmitral flow velocity/lateral mitral annulus myocardial velocity (E/e') to LA_S-S. We performed correlation and regression analyses of individual TOD with LA phasic functions, the LASI, and cardiovascular risk factors. Our findings showed that there was a trend toward a gradual increase in the LASI from controls to normal LA and enlarged LA patients and finally to hypertrophic LV patients. The LASI was significantly higher in Group III [0.28 (0.20, 0.38)] than in Group I [0.20 (0.16, 0.23)] and Group II [0.22 (0.18, 0.27)] and was the highest in Group IV [0.33 (0.26, 0.43)]. The LA reservoir and conduit function gradually decreased from Group I to Group IV. Multivariate regression analysis revealed that the LASI was independently correlated with individual TOD. In conclusion, abnormal LA mechanics precede LA enlargement and LVH, and an increased LASI can be used as a marker of early TOD in hypertension.

Percutaneous closure of the left atrial appendage: The value of real time 3D transesophageal echocardiography and the intraoperative change in the size of the left atrial appendage

OBJECTIVE

The aim of this study was to investigate the value of real time three-dimensional transesophageal echocardiography (RT3DTEE) in percutaneous closure of the left atrial appendage (LAAC). In addition, this study also explored the change in the size of the left atrial appendage (LAA) from 24 hours before the operation to just before implantation during the operation.

METHODS AND RESULTS

In a retrospective study, 32 patients underwent two-dimensional transesophageal echocardiography (2DTEE) and RT3DTEE 24 hours prior to operation and during operation. The maximal LAA orifice diameter (by 2DTEE, 22.7 ± 2.7 vs 24.6 ± 2.2 mm, P < 0.01; by RT3DTEE, 24.2 ± 2.9 vs 25.8 ± 2.7 mm, P < 0.01), the maximal landing zone diameter (by 2DTEE, 19.0 ± 2.8 vs 20.4 ± 2.8 mm, P < 0.01; by RT3DTEE, 20.4 ± 2.7 vs 22.6 ± 3.0 mm, P < 0.01), and the maximal depth diameter (by 2DTEE, 25.2 ± 3.2 vs 26.5 ± 3.0 mm, P < 0.01; by RT3DTEE, 26.4 ± 3.2 vs 27.5 ± 3.7 mm, P < 0.01) all increased significantly during the operation. The highest correlation (R) between the maximal landing zone diameter and the compressed occluder diameter was determined for RT3DTEE measurements during the operation (R = 0.90), whereas the landing zone diameter (R = 0.80) measured by 2DTEE was less correlated. In addition, our study showed that RT3DTEE was of great value in discriminating the LAA orifice shape, allowing differentiation of the LAA morphology and identification of the number of LAA lobes.

CONCLUSIONS

A certain amount of intravenous rehydration just before and during operation increased the LAA size significantly. The measurements by RT3DTEE showed a closer correlation to LAA occluder size than those by 2DTEE. The LAA displayed by RT3DTEE was more visible than that by 2DTEE.

Quantitative analysis of mitral valve morphology in atrial functional mitral regurgitation using real-time 3-dimensional echocardiography atrial functional mitral regurgitation

Background

Atrial fibrillation (AF) can result in atrial functional mitral regurgitation (MR), but the mechanism remains controversial. Few data about the relationship between the 3-dimensional morphology of the MV and the degree of MR in AF exist.

Methods

Real-time 3-dimensional transesophageal echocardiography (3D-TEE) of the MV was acquired in 168 patients with AF (57.7% persistent AF), including 25 (14.9%) patients with moderate to severe MR (the MR+ group) and 25 patients without AF as controls. The 3-dimensional geometry of the MV apparatus was acquired using dedicated quantification software.

Results

Compared with the group of patients with no or mild MR (the MR- group) and the controls, the MR+ group had a larger left atrium (LA), a more dilated mitral annulus (MA), a reduced annular height to commissural width ratio (AHCWR), indicating flattening of the annular saddle shape, and greater leaflet surfaces and tethering. MR severity was correlated with the MA area (r² = 0.43, P < 0.01) and the annulus circumference (r² = 0.38, P < 0.01). A logistic regression analysis indicated that the MA area (OR: 1.02, 95% CI: 1.01–1.03, P < 0.01), AHCWR (OR: 0.24, 95% CI: 0.14–0.35, P = 0.04) and MV tenting volume (OR: 3.24, 95% CI: 1.16–9.08, P = 0.03) were independent predictors of MR severity in AF patients.

Conclusions

The mechanisms of “atrial functional MR” are complex and include dilation of the MA, flattening of the annular saddle shape and greater leaflet tethering.

Assessment of left atrial mechanical function and synchrony in paroxysmal atrial fibrillation with two-dimensional speckle tracking echocardiography

BACKGROUND

The aim of this study was to investigate left atrial (LA) function and synchrony in paroxysmal atrial fibrillation (PAF) patients using two-dimensional speckle tracking echocardiography (STE).

METHODS

Forty-five PAF patients and 30 healthy controls were enrolled. LA peak ventricular systolic longitudinal strain (LA_S-S ) and strain rate (LA_SR-S ) and left atrial longitudinal strain (LA_S-A ) and strain rate (LA_SR-A ) during late diastole were determined using STE, and the standard deviation of the time to peak (TPSD) of the regional strains was calculated to quantify LA dyssynchrony. TPSD during ventricular systole and late diastole were named SDs and SDa, respectively.

RESULTS

Left atrial peak longitudinal strain during ventricular systole (LA_S-S ) (29.34±8.57 vs 36.73±6.13), LA_SR-S (1.27±0.311 vs 1.57±0.25), LA_S-A (13.11±4.91 vs 17.86±3.57), and LA_SR-A (-1.51±0.58 vs -1.90±0.30) were reduced in the PAF group compared with the controls (P<.05 for all). SDs (8.11±3.00% vs 4.67±1.48%) and SDa (5.57±2.26% vs 3.11±1.13%) were greater in PAF patients than in the controls (P<.05 for both). Furthermore, PAF patients with normal LA sizes exhibited lower LA_S-S (P<.05), LA_SR-S (P<.05), LA_S-A (P<.05), and LA_SR-A (P<.05) values and increased SDs (P<.05) and SDa (P<.05) values compared with the controls. Multivariate regression confirmed that SDs and SDa were powerful parameters for differentiating PAF patients from controls (SDs: sensitivity, 83%; specificity, 72%; SDa: sensitivity, 81%; specificity, 76%).

CONCLUSIONS

Left atrial (LA) dysfunction and dyssynchrony in PAF patients can be detected with STE even in the absence of LA enlargement. STE-derived SDs and SDa were powerful parameters for identifying PAF patients.

Transplantation of human umbilical cord mesenchymal stem cells in cochlea to repair sensorineural hearing

To examine if transplantation of human umbilical cord mesenchymal stem cells (UMSC) into cochlea can be used to repair sensorineural hearing. Here we transplanted the fifth and sixth generations of UMSCs through the subarachnoid cavity of congenital deaf albino pigs. Auditory brainstem responses (ABR) were measured before and after UMSC transplantation. Cochlear samples were collected at 2 hrs, 3 days, 1, 2, 3, 4 and 8 weeks after transplantation. Immunohistochemistry was used to detect the proliferated cell nuclear antigen (PCNA). The UMSCs were found in different regions of the cochlea, including the stria vascularis, the basal membrane and the spiral ganglions, 3 days to 4 weeks after the transplantation. UMSCs and their DNA were found also in the areas of the brain, the heart, the liver, the kidney and the lung. ABR tests displayed a new waveform in the congenital deaf albino pigs after the UMSCs transplantation. We conclude that human UMSCs injected into the subarachnoid space can migrate into the inner ear, the central nervous system and the periphery organs. The presence of UMSCs in the cochlea maybe associated with changes of ABR waveforms in the congenital deaf albino pigs.

Different Combinations of Right Ventricular Longitudinal Velocity and Displacement Can Be Applied Effectively for Diagnosis of Right Heart Failure in Chinese Patients

<strong>Background:</strong> The noninvasive evaluation of right ventricular function (RVF) in cardiovascular and pulmonary diseases remains a challenge. Internationally recommended echocardiographic parameters for the evaluation of RVF may not be applicable to China, because of the limited examination time per patient, the varying skill levels of ultrasonographers, inadequate allocation of professional specialties, and outdated instruments and equipment.<br /><strong>Methods:</strong> Sixty-two patients admitted for right heart failure and 52 healthy volunteers were included in the analysis. The tricuspid annular plane systolic excursion (TAPSE), peak systolic velocity in the tricuspid annulus of the right ventricular free wall (S′), myocardial performance index, right ventricular fractional area change, and Doppler peak strains in the base and mid cavity were evaluated and compared between groups.<br /><strong>Results:</strong> Compared with the control group, all RVF parameters in the right heart failure group showed significant deterioration (P &lt; .001). However, only TAPSE and S′ were finally included in the discriminant equation. The diagnostic cutoff values derived from the receiver operating characteristic curve were &lt;13.74 mm and &lt;9.5 cm/s, respectively. The highest specificity in the diagnosis of right heart failure (100%) was achieved using S′ &lt;9.5 cm/s, either alone or in combination with TAPSE &lt;13.74 mm. The highest diagnostic sensitivity (90.32%) was achieved using either TAPSE &lt;13.74 mm or S′ &lt;9.5 cm/s alone.<br /><strong>Conclusion:</strong> TAPSE and S′ are more suitable than other parameters for the diagnosis of right heart failure in Chinese patients. Different combinations of TAPSE and S′ can be applied effectively for the diagnosis of right heart failure.

A de novo silencer causes elimination of MITF-M expression and profound hearing loss in pigs

Background

Genesis of novel gene regulatory modules is largely responsible for morphological and functional evolution. De novo generation of novel cis-regulatory elements (CREs) is much rarer than genomic events that alter existing CREs such as transposition, promoter switching or co-option. Only one case of de novo generation has been reported to date, in fish and without involvement of phenotype alteration. Yet, this event likely occurs in other animals and helps drive genetic/phenotypic variation.

Results

Using a porcine model of spontaneous hearing loss not previously characterized we performed gene mapping and mutation screening to determine the genetic foundation of the phenotype. We identified a mutation in the non-regulatory region of the melanocyte-specific promoter of microphthalmia-associated transcription factor (MITF) gene that generated a novel silencer. The consequent elimination of expression of the MITF-M isoform led to early degeneration of the intermediate cells of the cochlear stria vascularis and profound hearing loss, as well as depigmentation, all of which resemble the typical phenotype of Waardenburg syndrome in humans. The mutation exclusively affected MITF-M and no other isoforms. The essential function of Mitf-m in hearing development was further validated using a knock-out mouse model.

Conclusions

Elimination of the MITF-M isoform alone is sufficient to cause deafness and depigmentation. To our knowledge, this study provides the first evidence of a de novo CRE in mammals that produces a systemic functional effect.

Electronic supplementary material

The online version of this article (doi:10.1186/s12915-016-0273-2) contains supplementary material, which is available to authorized users.

The protective effects of Masson pine pollen aqueous extract on CCl4-induced oxidative damage of human hepatic cells

OBJECTIVE

We observed the effects of Masson pine pollen aqueous extracts (MPPAE) on CCl4-induced oxidative damage of the human hepatic cell line L-02.

METHODS

We created an in vitro model of oxidative liver damage by treating L-02 human hepatic cells with 40 mmol/L CCl4. Effects of different concentrations of MPPAE on cell proliferation, morphology, and change of functional indexes were observed after addition of CCl4.

RESULTS

CCl4 was toxic to proliferation, cell morphology, and functionality of hepatic cells. It decreased proliferation by 29.3-38.4% and increased AST and ALT activities by 22.3% and 99.2%, respectively. The oxidative stress also disrupted hepatic cell growth and induced pyknosis. Although MPPAE did not prevent decreased proliferation of L-02 cells, the treatment alleviated some CCl4-induced cell morphology changes and inhibited the abnormal rise of ALT (39.8%-70.1%) and AST (14.75-27.25%) activities in a dose dependent manner. A high dose of MPPAE (400 mg/L) ameliorated nucleus deformation to an almost normal appearance.

CONCLUSIONS

According to our in vitro model, MPPAE specifically prevented the changes in cell morphology and functional injury caused by CCL4 treatment; however, it offered limited protection against damage-induced reduction of proliferation.

[Effects of zinc deficiency on the relevant immune function in rats with sepsis induced by endotoxin/lipopolysaccharide]

OBJECTIVE

To investigate the effects of zinc deficiency on the relevant immune function in rats with LPS-induced sepsis.

METHODS

Sixty rats were divided into low zinc group (LZ), normal zinc pair-fed group (NP), and normal zinc control group (NC) according to the random number table, with 20 rats in each group. The rats in group LZ were fed with low zinc diet, and the rats in group NP were fed with normal zinc diet, with the same intake as that of group LZ by manual control, and the rats in group NC were fed with normal zinc diet freely. After being fed for 7 d, the rats all fasted and were further divide into the below subgroups named LZ-LPS, LZ-normal saline (NS), NP-LPS, NP-NS, NC-LPS, and NC-NS according to the random number table, with 10 rats in each subgroup. Rats in the LPS subgroups were intraperitoneally injected with 1 mg/mL LPS solution with the dosage of 5 mg/kg, rats in the corresponding NS subgroups were intraperitoneally injected with equivalent NS. The rats were sacrificed at post injection hour 6 to collect blood, spleen, and thymus. The serum level of zinc was detected by inductively coupled plasma mass spectrometry, and the serum alkaline phosphatase (ALP) activity was detected by automatic blood biochemical analyzer. The body weight and weight of spleen and thymus of rats were weighed, and the indices of spleen and thymus were calculated. Six routine blood indices were examined by automatic blood cell analyzer. The serum levels of interferon gamma (IFN-γ), TNF-α, IL-4, and IL-10 were determined with ELISA, and the ratio of IFN-γ to IL-4 was calculated. Data were processed with one-way analysis of variance and SNK test.

RESULTS

(1) Serum levels of zinc and ALP activity in the LPS subgroups were significantly lower than those in the corresponding NS subgroups (with P values below 0.05). The two former indices in subgroups NP-NS and NC-NS were significantly higher than those in subgroup LZ-NS (with P values below 0.05). The two former indices in subgroups NP-LPS and NC-LPS were significantly higher than those in subgroup LZ-LPS (with P values below 0.05). (2) Body weight, spleen and thymus weight, indices of spleen and thymus in the LPS subgroups were similar with those in the corresponding NS subgroups (with P values above 0.05). The 4 former indices, except for body weight, in subgroups NP-NS and NC-NS were significantly higher than those in subgroup LZ-NS (with P values below 0.05). The 4 former indices, except for body weight, in subgroups NP-LPS and NC-LPS were significantly higher than those in subgroup LZ-LPS (with P values below 0.05). (3) Levels of leucocyte count in subgroups LZ-LPS and NP-LPS were significantly higher than those in the corresponding NS subgroups (with P values below 0.05). Level of leucocyte count in subgroup NC-NS was significantly higher than that in subgroup LZ-NS (P<0.05). Level of leucocyte count in subgroup NC-LPS was significantly lower than that in subgroup LZ-LPS (P<0.05). Levels of neutrophilic granulocyte count (NGC) and NG in the LPS subgroups were significantly higher than those in the corresponding NS subgroups (with P values below 0.05). The two former indices in subgroup NC-LPS were significantly lower than those in subgroup LZ-LPS (with P values below 0.05). Level of NG in subgroup NC-NS was significantly lower than that in subgroup LZ-NS (P<0.05). Levels of lymphocyte count and lymphocyte in subgroups LZ-NS, LZ-LPS, NP-NS, NP-LPS, NC-NS, and NC-LPS were respectively (1.8 ± 0.4) × 10⁹/L, (1.0 ± 0.3)× 10⁹/L, (2.6 ± 0.7) × 10⁹/L, (1.4 ± 0.4) × 10⁹/L, (3.3 ± 0.6) × 10⁹/L, (1.5 ± 0.5) × 10⁹/L, and 0.39 ± 0.10, 0.11 ± 0.03, 0.47 ± 0.12, 0.14 ± 0.04, 0.50 ± 0.09, 0.24 ± 0.07. The two former indices in the LPS subgroups were significantly lower than those in the corresponding NS subgroups (with P values below 0.05). The two former indices in subgroup NC-NS were significantly higher than those in subgroup LZ-NS (with P values below 0.05). The two former indices in subgroups NP-LPS and NC-LPS were significantly higher than those in subgroup LZ-LPS (with P values below 0.05). Level of lymphocyte count in subgroup NP-NS was significantly higher than that in subgroup LZ-NS (P<0.05). Levels of platelet count (PC) in subgroups NP-LPS and NC-LPS were significantly lower than those in the corresponding NS subgroups (with P values below 0.05). Levels of PC in subgroups NP-NS and NC-NS were significantly higher than those in subgroup LZ-NS (with P values below 0.05). Level of PC in subgroup NC-LPS was significantly higher than that in subgroup LZ-LPS (P<0.05). (4) Serum levels of TNF-α, IL-4, and IL-10 in each subgroup showed no significant differences (with P values above 0.05). Serum levels of IFN-γ and ratios of IFN-γ to IL-4 in subgroups LZ-NS, LZ-LPS, NP-NS, NP-LPS, NC-NS, and NC-LPS were respectively (75 ± 21), (233 ± 40), (80 ± 14), (345 ± 74), (66 ± 7), (821 ± 189) pg/mL, and 3.1 ± 1.0, 6.6 ± 1.7, 3.9 ± 1.7, 20.2 ± 8.3, 3.4 ± 1.5, 45.7 ± 7.6. The two former indices in the LPS subgroups were significantly higher than those in the corresponding NS subgroups (with P values below 0.05). The two former indices in subgroups NP-NS and NC-NS were similar with those in subgroup LZ-NS (with P values above 0.05). The two former indices in subgroups NP-LPS and NC-LPS were significantly higher than those in subgroup LZ-LPS (with P values below 0.05).

CONCLUSIONS

Zinc deficiency can induce the atrophy of spleen and thymus, and reduction of peripheral blood lymphocyte. In sepsis, zinc deficiency can further decrease the production of IFN-γ, thus making the cytokines of Th1/Th2 shift to Th2 and the immune imbalance worse.

Predictive value of brachial-ankle artery pulse wave velocity to heart failure with preserved ejection fraction in hospitalised patients with acute dyspnoea

Objective:

To explore the predictive value of the brachial-ankle artery pulse wave velocity (baPWV) for heart failure with preserved ejection fraction (HFpEF).

Methods:

Echocardiographic data, B-type natriuretic peptide (BNP) level, and baPWV were assessed in 111 consecutive patients admitted for acute dyspnea. The patients were divided into the HFpEF group (n=71) and the control group (n=40).

Results:

Multivariate logistic regression analyses revealed that the ratio of the early mitral inflow velocity to the tissue Doppler velocity (E/e’) at the lateral mitral annulus, BNP, and baPWV were independently predictive of HFpEF. Adding the baPWV to E/e’ at the lateral annulus and to the BNP resulted in an increase in the area under the curve (AUC) to 0.855 (vs. lateral E/e’ alone, P=0.02) or 0.880 (vs. BNP alone, P=0.02), respectively. The AUC of the three combining indicators including the lateral E/e’, BNP, and baPWV was 0.910 (vs. E/e’ lateral alone, P<0.001; vs. BNP alone, P=0.001). The diagnostic accuracy was improved significantly after adding the baPWV to the diagnostic criteria of the 2007 ESC consensus statement (net reclassification improvement 0.127, P=0.02).

Conclusions:

Adding the baPWV to the current diagnostic indicators of the 2007 ESC consensus statement could increase the accuracy of predicting HFpEF.

Anti-fibrotic effects of the Masson pine pollen aqueous extract on hepatic fibrosis rat model

AIM

To observe the antifibrotic effects of Masson Pine Pollen aqueous extract.

METHODS

Adult Sprague-Dawley rats were randomly divided into control (CG), hepatic fibrosis model (MG), MPPAE low dose (LG), MPPAE high dose (HG), and MPP original powder (MPPOP; OG) groups. Each group was treated with specific protocols and sacrificed 8 weeks later. Multiple indicators such as serum transaminase, HE staining of the liver tissue, and relevant indexes to fibrosis were determined.

RESULTS

Severe hyperplasia of fibrous connective tissues was observed in livers of the MG group rats, while aspartate transaminase and alanine transaminase levels and collagen content obviously increased, superoxide dismutase and glutathione peroxidase activities and MMPs expression decreased, malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine concentrations increased, while mRNA expressions of hepatic stellate cell (HSC)-related cytokines such as transforming growth factor-β1 and platelet-derived growth factor, transcription factors such as nuclear factor-κB p65, and signaling protein α-smooth muscle actin were all increased significantly.

CONCLUSIONS

MPPAE effectively inhibited the fibrotic process in this CCl4-induced hepatic fibrosis rat model. It may be associated with synergic functions of antioxidant activity, inhibitory activity on HSC proliferation, collagen synthesis, and MMPs expression induction.

Prognostic Value of Speckle Tracking Echocardiography in Patients with ST-Elevation Myocardial Infarction Treated with Late Percutaneous Intervention

BACKGROUND

Left ventricular remodeling (LVr) is common after ST-segment elevation myocardial infarction (STEMI). The aim of this study was to evaluate the prognostic value of speckle tracking echocardiography (STE) for predicting LVr 6-9 months after late percutaneous coronary intervention (PCI) in patients with STEMI.

METHODS

Patients with first STEMI who accepted late PCI were enrolled. Echocardiography was performed within 48 hours of admission. Six to nine months after MI, an echocardiography examination was repeated. LVr was defined as >15% increase in LV end-systolic volume (LVESV) after 6 months.

RESULTS

One hundred and twenty-seven patients were divided into two groups: 86 patients without LVr and 41 patients with LVr. There were significant differences in the global longitudinal strain (GLS), SD of time to peak longitudinal systolic strain (longitudinal Ts-SD), longitudinal postsystolic index, radial strain (RS), and SD of time to peak radial systolic strain (Radial Ts-SD). In multivariate logistic regression analysis, the GLS(odds ratio [OR] = 0.39, 95% confidence interval [CI] = 0.26-0.57, P < 0.01), and RS(OR = 1.07, 95% CI = 1.02-1.13, P = 0.01) were determinants of LVr. A receiver operating characteristic curve showed that the GLS predicted LVr with an optimal cutoff value of -10.85 (sensitivity: 89.7%, specificity: 91.7%). During clinical follow-up for 16.9 ± 1.6 months, death or congestive heart failure developed in 12 patients (9.4%), and the baseline ejection fraction (OR = 1.91, 95% CI = 1.18-3.1, P = 0.009) and GLS (OR = 0.56, 95% CI = 0.34-0.91, P = 0.02) were independent predictors.

CONCLUSION

In patients with STEMI treated with late percutaneous coronary intervention, the GLS as measured by STE is a strong predictor of LVr and adverse events.

Noninvasive assessment of left atrial phasic function in patients with hypertension and diabetes using two-dimensional speckle tracking and volumetric parameters

OBJECTIVE

To evaluate the left atrial phasic function of hypertensive patients with or without coexisting diabetes using two-dimensional speckle tracking echocardiography (2DSTE)-based strain and strain rate imaging and volumetric parameters.

METHODS

The study included an isolated hypertension group (HT group) comprising 99 patients, a hypertension and diabetes group (HT + DM group) comprising 65 patients, and 26 age-matched healthy controls. The 2DSTE-based strain and strain rate images were studied, and the following parameters were measured: peak left atrial longitudinal strain (LAS-S ), early diastolic (LAS-E ) and late diastolic (LAS-A ) atrial longitudinal strains, and systolic (LASR-S ), early diastolic (LASR-E ) and late diastolic (LASR-A ) strain rates.

RESULTS

The LAS-S and LASR-S were lower in the HT group and the HT + DM group compared with the control group (P < 0.001). The LAS-E and LASR-E were lower in the HT group (14.9 ± 5.5% and -1.1 ± 0.4/sec, respectively) than in the control group (22.1 ± 8.3% and -1.7 ± 0.6/sec, respectively) (P < 0.001), and they were further depressed in the HT + DM group (12.3 ± 6.3% and -1.0 ± 0.4/sec, respectively) (P < 0.05). There were no significant differences in LAS-A or LASR-A among the 3 groups (P > 0.05). Multivariate regression analysis revealed that HT and DM were independently related to LAS-E and LASR-E .

CONCLUSIONS

Hypertension can lead to abnormal left atrial reservoir and conduit functions, and coexisting diabetes can further impair conduit function. 2DSTE-derived strain and strain rate imaging are sensitive methods for evaluating left atrial phasic function.

Cytokines, liver fibrosis, and principles of nutritional support in patients with liver fibrosis

The rapid development of molecular biology has provided new paths for and led to great breakthroughs in the treatment of liver fibrosis. Now the research of targets for anti-fibrosis therapy mainly focuses on hepatic stellate cells (HSC) and cytokines related to HSC activation. Researchers are getting more concerned about the features of nutritional metabolism in patients with liver fibrosis and their relationship with prognosis because of special roles the liver plays in nutritional metabolism. Reasonable principles of nutritional support can help ameliorate symptoms, reduce complications and facilitate recovery in patients with liver fibrosis.

Effects of different proteins on the metabolism of Zn, Cu, Fe, and Mn in rats

Many factors are known to influence trace element metabolism and one of them is dietary protein. The present study examines the effects of casein, soybean protein, and peanut protein on the metabolism of the Zn, Cu, Fe, and Mn in growing rats. The results showed that Zn, Fe, and Mn excretions in the feces of peanut protein-fed rats (PPFRs) were similar to that of casein-fed rats (CPFRs) (p > 0.05), whereas all of the Zn, Cu, Fe, and Mn excretions in the urine of PPFRs were significantly higher than that of CPFRs (p < 0.05), but its apparent absorption rate (AAR) of Cu, Fe and its apparent retention rate (ARR) of Cu were all higher than that of CPFRs (p < 0.05). Hepatic Zn content of soybean protein-fed rats (SPFRs) was higher than that of CPFRs and PPFRs (p < 0.05 respectively) and serum, renal, and femoral Cu contents of SPFRs were significantly lower; however, hepatic Cu, and renal Mn contents were significantly higher than that of CPFRs (p < 0.05, respectively); The hepatic Fe content of SPFRs was significantly higher than that of CPFRs and PPFRs (p < 0.01, respectively). To sum up, compared to casein, soybean protein might be a good dietary source to make up for Zn and Fe deficiency, and also peanut protein to make up for Cu and Fe deficiency.

[Effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats]

OBJECTIVE

To explore the effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats.

METHODS

Eighty SD rats were randomly divided into C group (control group without scald, n = 8), and N, W, H groups (each consisting of 24 rats), in which the rats were exposed to scalding resulting in partial thickness burns covering 15% of the total body surface area on the back, and then they were fed with diets containing zinc 40 microg/g in N and W groups, and 80 microg/g in H group. A cream containing zinc 761.1 microg/g was applied on the wound in W group at the same time. Eight rats of each group were sacrificed on day 1, 3 and 7 after scald respectively. Venous blood and samples of liver, femur and scald skin were harvested. Zinc and calcium contents in serum and tissues were determined with atomic absorption spectrophotometer.

RESULTS

The serum Zn(2+) levels in N, W groups were lower than C group, however, it was obviously higher in H group (up to 16.2 micromol/L) on day 1 after scald. The liver Zn(2+) showed an increasing tendency in all groups, while Ca(2+) level declined in H group, but increased in N, W group. The bone Zn(2+) and Ca(2+) levels showed a progressive declination in all groups from day 1 to 7 after scald. The changes were more obviously in N group than H group (P < 0.05). The Zn(2+) content of the scalded skin increased obviously in H group on first day after scald and in W group on 7th day after scald. The Ca(2+) contents of scalded skin showed marked increases in all groups, especially in N group, but least in W group.

CONCLUSION

There are obvious changes in Zn(2+) and Ca(2+) contents of serum and tissues after scald injury and zinc supplementation. The effects of zinc supplementation on calcium level in the tissue need to be further studied.

The effect of metal copper on fracture healing in chicken

OBJECTIVE

To observe the effect of copper on bone fracture healing.

METHODS

160 growing chickens aged 70 days were fed in 32 cages, each consisting of five. The fracture with 1 approximately 2 mm defects at the bilateral radius of wings was created by osteotomy. The chickens were divided into four groups, 40 each. Every morning, chickens of the first group, served as controls, were fed orally 0.8% Na-CMC solution (sodium carboxymethyl cellulose), those of the other three groups were fed with copper-Na-CMC suspension (copper powder suspended in 0.8% Na-CMC) with different doses of 20, 40 and 80 mg Cu/kg body weight. Each group was sacrificed 14, 21, 28 and 35 days postoperatively. Liver was taken for analysis of Cu and Zn. Both radius were removed by dissection. CT was performed quantitatively for the ment of the gray values of the callus. The biomechanical properties of the healing radius were analyzed by a three point bending test. Afterwards, the contents of calcium, magnesium, phosphorus, copper, zinc, iron and hydroxyproline in the callus were determined.

RESULTS

The gray values of the callus increased along with the increase of copper dose and the duration of observation. 21 and 35 days after operation, the gray values of the callus were significantly higher in the high-Cu group than in the controls respectively (909 +/- 220 vs. 597 +/- 155; 973 +/- 100 vs. 763 +/- 179 HU, P < 0.05). The level of calcium and magnesium in the callus 35 days after operation was much higher in the mid and high Cu groups than in the controls respectively (Ca: 177 +/- 26.7, 176 +/- 20.5 and 137 +/- 34.7 mg/g; Mg: 2.98 +/- 0.57, 3.06 +/- 0.46 and 2.43 +/- 0.53 mg/g P < 0.05). The contents of hydroxyproline in the callus 35 days after operation were significantly higher in the high-Cu group than in the controls (34.23 +/- 1.96 vs. 32.17 +/- 1.93 mg/g respectively). The biomechanical properties of the repaired radius had a better improvement tendency in the three Cu-fed groups than in the controls.

CONCLUSION

Copper is helpful in fracture healing; however, the effect of copper on fracture healing needs further study.

[Influence of oral administration of realgar on contents of copper, zinc and selenium in rat tissues]

OBJECTIVE

To investigate the changes of copper, zinc and selenium levels in rat tissues after long-term oral administration of Realgar.

METHODS

Rats were given Realgar with dosage of 50, 150, 450 mg.kg-1.d-1 for 5 weeks, and the concentrations of copper, zinc and selenium in different rat tissues as well as the contents of metallothionein in rat liver and kidney were determined with atomic absorption and hydride generation-atomic fluorescent technique. The total amount of copper excreted from feces and urine of each rat 5 days before the rat was killed was also measured.

RESULTS

No significant changes of levels of copper, zinc and selenium in rat tissues were found after administration of low and middle dosages of Realgar. But higher dosage (450 mg.kg-1.d-1) of Realgar administration could induce a small but significant decrease of zinc concentration in hearts and a increase of copper contents in spleen and tibia, as well as twice more copper concentration of kidney.

CONCLUSION

Copper deposit in kidney was the most significant change found among the trace elements levels in rat tissues, and this might be one of the mechanisms for kidney toxicity of Realgar.